button {
    margin: 10px;
    padding: 10px 20px;
    font-size: 18px;
    border: 2px solid #ccc;
    border-radius: 8px;
    transition: all 0.2s ease;
}


/* :active 鼠标按下时 */
button:active {
    background-color: blue;
    color: white;
    transform: scale(0.95);
}

